Among various film-forming techniques, solution film-forming techniques are more and more attractive. The so-called solution film-forming is processing a desired material, for example dispersing into nanoscale minute particles, then dissolving in a corresponding solvent, next depositing this solution on the surface of a substrate by using another device, and forming a desired thin-film on the surface of the substrate after the solvent is evaporated.
Inkjet printing is relatively important one among solution film-forming techniques, and has been widely used for producing color filters, organic thin film transistors, metal electrodes, three-dimensional isolation walls, and the like in light-emitting display and for producing light-emitting devices due to the advantages of simple operation, low cost, simple process, and easiness of achieving large size. All of these have very good effects. In particular, in the processing and production of self light-emitting devices such as organic light-emitting devices (OLED) and the like, inkjet printing has attracted much attention due to multiple advantages of low cost, high efficiency, and the like.